The COVID-19 pandemic has underscored the significance of antibacterial protective materials. Utilizing high-performance antibacterial masks proves to be effective in preventing the spread of respiratory diseases. Herein, we demonstrate a self-cleaning antibacterial mask constructed from the fiber@ZnO composite membrane, utilizing the strong interfacial adhesion of polydopamine (PDA). With a ZnO NPs immersion solution concentration of 1.0 mg mL⁻¹, the ZnO NP content in fiber@ZnO reaches 6.5 %. The fiber@ZnO demonstrates bactericidal rates exceeding 99% against Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria, and exhibits an inhibition rate exceeding 99.99% against the H1N1 influenza virus. The hydrogen bonding and electrostatic interaction between ZnO nanoparticles (NPs) and PDA can keep a stable combination of NPs and fiber. Antibacterial masks constructed by the fiber@ZnO composite membrane exhibit superior self-cleaning performance and effectively eliminate pathogenic bacteria in aerosols compared with commercial N95 masks. The mussel-bionic strategy presents a viable approach for developing novel antibacterial fibers, with significant application potential in reducing the risk of human infection and preventing the re-transmission of pathogens.

Easy non-radiative decay property of long-lived triplet excitons in aqueous solution obstructs their applications in aquatic surroundings. Recently reported phosphorescence phenomena in aqueous solution have excited researchers enormously but achieving full-color water-soluble phosphorescent carbon nanodots (CNDs) is still a challenging issue. Herein, full-color phosphorescence of water-soluble CNDs has been demonstrated by triggering their triplet excitons through nanospace domain confinement, and Förster energy resonance transfer is used for further tuning phosphorescence range. The phosphorescence spans across most of the visible spectrum, ranging from 400 to 700 nm. In an aqueous solution, the CNDs exhibits blue, green, and red phosphorescence, lasting for approximately 6, 10, and 7 s, respectively. Correspondingly, the phosphorescence quantum yields are 11.85%, 8.6% and 3.56%, making them readily discernible to the naked eyes and laying a solid foundation for practical application. Furthermore, phosphorescence flexible optical display and bioimaging have been demonstrated by using the multicolor CNDs-based nanomaterials, showing distinct superiority for accuracy and complete display and imaging in complex emission background.

The emergence of novel self-powered humidity sensors has attracted considerable attention in the fields of smart electronic devices and personal healthcare. Herein, self-powered humidity sensors have been fabricated using a moisture-driven energy generation (MEG) device based on asymmetric tubular graphitic carbon nitride (g-CN) films prepared on anodized aluminum (AAO) template. At a relative humidity (RH) of 96%, the MEG device can provide an open-circuit voltage of 0.47 V and a short-circuit current of 3.51 μA, with a maximum output power of 0.08 μW. With inherent self-powered ability and humidity response via current variation, an extraordinary response of 1.78 × 10⁶% (41%–96% RH) can be gained from the MEG device. The possible power generation mechanism is that g-CN/AAO heterostructure can form ion gradient and diffusion under the action of moisture to convert chemical potential into electrical potential, evoking a connaturally sensitive response to humidity. Self-powered respiration monitoring device based on the sensor is designed to monitor human movement (sitting, warming up, and running) and sleep status (normal, snoring, and apnea), maintaining excellent stability during cumulative 12-h respiration monitoring. This self-powered humidity sensing technology has promising potential for extensive integration into smart electronic and round-the-clock health monitoring devices.

Recently, the chemiluminescence (CL) induced by carbon nanodots (CDs) has intrigued researchers’ extensive interests in various applications due to its special light emission principle. However, the difficulty of synthesizing chemiluminescent CDs with full-spectrum emission severely hinders the further regulation of the CL emission mechanism. Herein, the multi-color-emissive chemiluminescent CDs are rational designed and further synthesized by regulating the sp²-hybrid core and sp³-hybrid surface from the citrate-ammonia molecular in a single solvothermal reaction. More experimental characterizations and density functional theory calculations reveal that the higher temperature can promote the crosslinking polymerization/carbonization of carbon core and the higher protonation of solvent can determine the core size of final CDs, resulting in the variant CL emission from molecular-, crosslinking- and core-states. Thus, the CL emission of the CDs can be further synthesized by tuning the luminescence chromophores in the formation process via regulating the temperature and solvent, enabling the applications of the CL CDs in illumination and information encryption. This study paves a new technology to understand the luminescence of CDs and affords an industry translational potential over traditional chemiluminescent molecular.

The spread of diseases caused by bacterial adhesion and immobilization in public places constitutes a serious threat to public health. Prevention of bacteria spread by the construction of an antibacterial surface takes precedence over post-infection treatment. Herein, we demonstrate an effective antibacterial surface with strong wear resistance by constructing cationic engineered nanodiamonds (C-NDs). The C-NDs with positive surface potentials interact effectively with bacteria through electrostatic interactions, where the C-NDs act on the phospholipid bilayer and lead to bacterial membrane collapse and rupture through hydrogen bonding and residual surface oxygen-containing reactive groups. In this case, bactericidal rate of 99.99% and bacterial biofilm inhibition rate of more than 80% can be achieved with the C-NDs concentration of 1 mg/mL. In addition, the C-NDs show outstanding antibacterial stability, retaining over 87% of the antibacterial effect after stimulation by adverse environments of heat, acid, and external abrasion. Therefore, an antibacterial surface with high wear resistance obtained by integrating C-NDs with commercial plastics has been demonstrated. The antibacterial surface with a mass fraction of 1 wt.% C-NDs improved abrasion resistance by 3981 times, with 99% killing of adherent bacteria. This work provides an effective strategy for highly efficient antibacterial wear-resistant surface, showing great practical applications in public health environments.

Humidity sensors with high sensitivity, rapid response, and facile fabrication process for contactless sensing applications have received considerable attention in recent years. Herein, humidity sensors based on hexagonal boron nitride (h-BN) nanosheets that are synthesized by a facile ultrasonic process have been fabricated, which display an ultrahigh sensitivity of 28,384% at 85% relative humidity (RH), rapid response/recovery time (3.0/5.5 s), and long-term stability in a wide humidity detection range (11%–85% RH), superior to most of the reported humidity sensors. The high sensitivity can be ascribed to the massive hydrophilic functional groups absorbed on the h-BN nanosheet surface. Benefiting from the high humidity sensing performances, contactless Morse code messaging and human writing and speech recognition have been demonstrated. This work demonstrates the great potential of the high-performance h-BN nanosheet-based humidity sensors for future contactless sensing devices.

Continuous mechanoluminescence (ML) fibers and fiber-woven textiles have the potential to serve as new wearable devices for sensors, healthcare, human–computer interfacing, and Internet of Things. Considering the demands on wearability and adaptability for the ML textiles, it is essential to realize the continuous synthesis of fiber, while maintaining a desired small diameter. Here, we develop a novel adhere-coating method to fabricate ML composite fiber, consisting of a thin polyurethane (PU) core and ZnS:Cu/polydimethylsiloxane (PDMS) shell, with the outer diameter of 120 μm. By diluting PDMS to tune the thickness of liquid coating layer, droplets formation has been effectively prevented. The composite fiber exhibits a smooth surface structure and superior ML performances, including high brightness, excellent flexibility, and stability. In addition, a weft knitting textile fabricated by the continuous ML fiber can be easily delighted by manually stretching, and the ML fibers can emit visible signals upon human motion stimuli when woven into commercial cloth. Such continuous ultra-fine ML fibers are promising as wearable sensing devices for human motion detection and human–machine interactions.

As a typical two-dimensional material, graphitic carbon nitride (g-CN) has attracted great interest because of its distinctive electronic, optical, and catalytic properties. However, the absence of a feasible route toward large-area and high-quality films hinders its development in optoelectronics. Herein, high-quality g-CN films have been grown on Si substrate via a vapor-phase transport-assisted condensation method. The g-CN/Si heterojunction shows an obvious response to ultraviolet–visible-near infrared photons with a responsivity of 133 A·W⁻¹, which is two orders of magnitude higher than the best value ever reported for g-CN photodetectors. A position-sensitive detector (PSD) has been developed using the lateral photovoltaic effect of the g-CN/Si heterojunction. The PSD shows a wide response spectrum ranging from 300 to 1,100 nm, and a position sensitivity and rise/decay time of 395 mV·mm⁻¹ and 3.1/50 μs, respectively. Moreover, the application of the g-CN/Si heterojunction photodetector in trajectory tracking and acoustic detection has been realized for the first time. This work unveils the potential of g-CN for large-area photodetectors, and prospects for their applications in trajectory tracking and acoustic detection.

Ultraviolet position-sensitive detectors (PSDs) are expected to undergo harsh environments, such as high temperatures, for a wide variety of applications in military, civilian, and aerospace. However, no report on relevant PSDs operating at high temperatures can be found up to now. Herein, we design a new 2D/3D graphitic carbon nitride (g-C₃N₄)/gallium nitride (GaN) hybrid heterojunction to construct the ultraviolet high-temperature-resistant PSD. The g-C₃N₄/GaN PSD exhibits a high position sensitivity of 355 mV mm⁻¹, a rise/fall response time of 1.7/2.3 ms, and a nonlinearity of 0.5% at room temperature. The ultralow formation energy of −0.917 eV atom⁻¹ has been obtained via the thermodynamic phase stability calculations, which endows g-C₃N₄ with robust stability against heat. By merits of the strong built-in electric field of the 2D/3D hybrid heterojunction and robust thermo-stability of g-C₃N₄, the g-C₃N₄/GaN PSD delivers an excellent position sensitivity and angle detection nonlinearity of 315 mV mm⁻¹ and 1.4%, respectively, with high repeatability at a high temperature up to 700 K, outperforming most of the other counterparts and even commercial silicon-based devices. This work unveils the high-temperature PSD, and pioneers a new path to constructing g-C₃N₄-based harsh-environment-tolerant optoelectronic devices.

Ga₂O₃ has been regarded as a promising material for solar-blind detection due to its ultrawide bandgap and low growth cost. Although semiconductor microwires (MWs) possess unique optical and electronic characteristics, the performances of photodetectors developed from Ga₂O₃ MWs are still less than satisfactory. Herein, we demonstrate high-performance solar-blind photodetectors based on Sn-doped Ga₂O₃ MWs, possessing a light/dark current ratio of 10⁷ and a responsivity of 2,409 A/W at 40 V. Moreover, a 1 × 10 solar-blind photodetector linear array is developed based on the Sn-doped Ga₂O₃ MWs via a patterned-electrodes method. And clear solar-blind images are obtained by using the photodetector array as the imaging unit of a solar-blind imaging system. The results provide a convenient way to construct high-performance solar-blind photodetector arrays based on Ga₂O₃ MWs, and thus may push forward their future applications.